1. Field of the Invention
This invention relates to a magnetic head device in which a slider having a magnetic head loaded thereon is mounted on a gimbal having a thin-film lead wire patterned thereon and the thin-film lead wire has its terminals connected to terminals of the magnetic head, and which may be suitably used for a hard disc device.
2. Description of the Related Art
A magnetic head device used for a magnetic recording device, such as a hard disc device, includes a base plate 101, a load beam 102 mounted on the base plate 101, a gimbal 103 mounted on the distal end of the load beam 102, and a slider 104 having loaded thereon a magnetic head 106 mounted on the gimbal 103, as shown in FIG. 1.
The load beam 102, functioning as a suspension for thrusting the slider 104 against a recording medium during recording/reproduction, includes an arm mounting portion 102a, to which the base plate 101 is mounted, an elastic portion 102b, bent at a pre-set angle for operating as an elastic portion, a tough portion 102c bent on both sides for being rendered tough, and a gimbal mounting portion 102d mounting the gimbal. When the magnetic head device is assembled on the magnetic recording device, the arm mounting portion 102a, to which is mounted the base plate 101, is mounted on an arm designed for moving the magnetic head device.
The gimbal 103, mounted on the distal end of the load beam 102, that is the gimbal mounting portion 102d, is configured for not obstructing movement of the slider 104. The gimbal 103 is formed with an opening 103a around a mounting portion for the slider 104 for permitting the slider 104 to be moved in both the pitching and rolling directions. By the gimbal 103 having such opening 103a, the slider 104 may be moved in both the pitching and rolling directions, such that the slider 104 may be maintained at a constant floating height on the recording medium during recording/reproduction irrespective of, for example, surface states of the recording medium.
The slider 104, mounted on the gimbal 103, is formed with the magnetic head 106 comprised of a magnetic core and a coil. For recording/reproduction, the magnetic head 106 is floated on the recording medium along with the slider 104, and records and/or reproduces data on or from the recording medium in the thus floated state.
A lead wire 105 is lead out at a terminal 104a of the magnetic head 106. The lead wire 105 is lead along the gimbal 103 and the load beam 102 to the arm so as to be connected to an external circuit.
With such magnetic head device, as the magnetic recording medium is reduced in size or increased in capacity, the size of the slider 104 tends to be reduced, while the float amount of the slider 104 during recording/reproduction also tends to be diminished. Specifically, the slider 104 is not more than 2.0 mm or less in length, not more than 1.6 mm or less in width and not more than 0.43 mm in height, with the amount of float during recording/reproduction being not more than 0.1 .mu.m.
However, as the slider 104 is reduced in size and the amount of float is decreased, the effect of the toughness of the lead wire 105 connected to the terminals 104a of the magnetic head 106 becomes significant with respect to the movement of the slider 104. That is, movement of the slider 104 becomes unstable under the effect of toughness of the lead wire 105, such that the amount of float of the slider 104, for example, is changed, thus disabling regular recording/reproduction.
For resolving this problem, a method has been developed which consists in forming a thin-film lead wire on the gimbal 103. With this method, the lead wire 105 is not connected to the terminal 104a of the magnetic head 106, but a thin-film lead wire is previously formed on the gimbal 103 and the terminal of the thin-film lead wire is connected to the terminal 104a of the magnetic head 106. This significantly diminishes the effect of the lead wire on the movement of the slider 104.
An instance of connecting the terminal of the thin-film lead wire to the terminal of the magnetic head is described in, for example, JP Patent Kokai Publication JP-A-6-215513. In the instance described in JP Patent Kokai Publication JP-A-6-215513, a thin-film lead wire 111 is previously formed on the gimbal 110, as shown in FIG. 2. Au balls 115 are arranged between a terminal 112 of the thin-film lead wire 111 and a terminal 114 of a magnetic head 113, using an Au ball bonder device, and the thin-film lead wire 111 has its terminals 112 connected to terminals 114 of the magnetic head 113.
However, if the terminals 112 of the thin-film lead wire 111 are connected in this manner to the terminals 114 of the magnetic head 113 using the Au balls 115, the Au balls 115, the terminals 112 of the thin-film lead wire 111 and the terminals 114 of the magnetic head 113 need to be in register with one another with high precision with the progress in the size reduction of the magnetic head 113, such that it becomes difficult to connect the terminals 112 of the thin-film lead wire 111 to the terminals 114 of the magnetic head 113 reliably. In addition, with the progress in size reduction of the magnetic head 113, the terminals 112 of the thin-film lead wire 111 and the terminals 114 of the magnetic head 113 are also reduced in size and hence the Au balls 115 also have to be reduced in size, such that it becomes difficult to connect the terminals 112 of the thin-film lead wire 111 to the terminals 114 of the magnetic head 113 reliably.
Thus, with the use of the thin-film lead wire 111, it is difficult to connect the terminals 112 of the thin-film lead wire 111 to the terminals 114 of the magnetic head 113 reliably, such that it is becoming crucial to enable reliable connection of the terminals 112 of the thin-film lead wire 111 to the terminals 114 of the magnetic head 113 in an easy manner.
If the thin-film lead wire is used, the effect of toughness of the lead wire for the slider movement can be reduced significantly, as explained above. However, if the slider is reduced further in size, it becomes difficult to override the effect of the toughness of the thin-film lead wire. That is, with the conventional thin-film lead wire, a Cu pattern 122 is formed on an insulating layer 121 formed on the gimbal 120, and a protective layer 123 of, for example, polyimide, is formed on the Cu pattern 122, as shown in FIG. 3. Thus the conventional thin-film lead wire is increased in toughness. Consequently, with the progress in reduction in size of the slider, it becomes difficult to override the effect of the toughness of the thin-film lead wire on the slider movement, such that some means need to be provided for decreasing the toughness of the thin-film lead wire.